The present invention relates to an electromagnetic actuating apparatus. Such electromagnetic actuating apparatuses which,—generically—are described for instance in DE 102 40 774 A1 of the applicant, are used for a variety of applications, wherein in particular the use as actuator for a camshaft adjustment device of a motor vehicle engine represents a preferred field of use. Here, for instance, the armature unit (typically constructed in the manner of a tappet) interacts with an end-side engagement region with an associated actuating groove or suchlike actuating partner of the internal combustion engine.
Not least owing to the characteristics due to structural space in such a location of use, the installation geometry of a known electromagnetic actuating apparatus of the generic type is frequently important; for instance in the example case of application of the camshaft adjustment and a plurality of actuators provided adjacent to one another (and typically with tappets aligned parallel to one another), radial dimensions (i.e. running transversely to a direction of movement) which are as compact as possible are a particular concern here, in order to be able to place for instance adjacent actuators are close to one another as possible; such a configuration then enables for instance the carrying out of several different actuation operations at the actuating partner, for instance the engaging in or respectively interacting with a plurality of actuating grooves provided adjacent to each other.
The geometric dimensions of generic electromagnetic actuating apparatuses can not, however—as a matter of principle—be minimized arbitrarily, thus for instance electromagnetic actuating forces of such an apparatus which are to be achieved, predetermined dynamic characteristics (actuating times) or suchlike constraints determine necessary minimum dimensions of the electromagnetic components which are involved.
Accordingly, it is important that other assemblies, for instance an enclosed housing or suchlike do not bring any significant (for instance radial) increase in dimension, so as not to have a disadvantageous influence on the compactness of a desired arrangement on electromagnetic actuating apparatuses, for instance a plurality of actuators which are to be provided adjacent to one another with the formation of a minimum spacing.
DE 10 2007 028 600 A1 of the applicant illustrates such a case of application of a plurality of movable armature units (parallel to one another, here); however, the solution described here is special, causes high expenditure in terms of installation and adjustment and is not generally able to be transferred to installation situations which require compact installation dimensions of the electromagnetic actuating apparatuses which are to be used.
The coil units described in this prior art, in this respect generically, also have the disadvantage that the connection contacts associated therewith (not shown in further detail) project radially (i.e. transversely to a respective axial direction of movement of the armature units), with the purpose, due to manufacturing technology, of electrically and mechanically connecting connection contacts, associated with a respective winding, to connecting structures (connecting means) in the respective housing, so that then via these connecting means a coupling can take place to a plug section, provided typically on the edge side on the housing. Via this plug section (which depending on the purpose of use can be embodied so as to be multipolar, in a bush-like manner or in another suitable manner), the coupling then takes place by means of conventional control wires to suitable control electronics.
In the currently prevailing mass production technology, the described connection between connection contact (the winding), which generally projects radially from the coil former (typically made from plastic), and the connecting means takes place here by a welded connection.
A corresponding welding tongs or suchlike element of an automatic welding machine overlaps, for this purpose, the partners which are to be connected and produces a welded connection in an otherwise known manner.
A disadvantage in this (otherwise proven and effective) method is that through the lateral (radial) projecting of the connection contact together with associated connection partner of the electrical connecting means, an effective diameter of the actuating apparatus is increased in size; thus, indeed, sufficient space must exist from the radial direction for the engagement of the welding device for producing the welded connection. This, in turn, is disadvantageous for the described requirements of compactness, in particular concerning as close and compact a construction density as possible of actuating apparatuses which are, or are to be provided, adjacent to one another.